Hypertonic saline attenuates TNF-alpha-induced NF-kappaB activation in pulmonary epithelial cells.
Resuscitation with hypertonic saline (HTS) attenuates acute lung injury (ALI) and modulates postinjury hyperinflammation. TNF-alpha-stimulated pulmonary epithelium is a major contributor to hemorrhage-induced ALI. We hypothesized that HTS would inhibit TNF-alpha-induced nuclear factor (NF)-kappaB proinflammatory signaling in pulmonary epithelial cells. Therefore, we pretreated human pulmonary epithelial cells (A549) with hypertonic medium (180 mM NaCl) for 30 min, followed by TNF-alpha stimulation (10 ng/mL). Key regulatory steps and protein concentrations in this pathway were assessed for significant alterations. Hypertonic saline significantly reduced TNF-alpha-induced intercellular adhesion molecule 1 levels and NF-kappaB nuclear localization. The mechanism is attenuated phosphorylation and delayed degradation of IkappaB alpha. Hypertonic saline did not alter TNF-alpha-induced p38 mitogen-activated protein kinase phosphorylation or constitutive vascular endothelial growth factor expression, suggesting that the observed inhibition is not a generalized suppression of protein phosphorylation or cellular function. These results show that HTS inhibits TNF-alpha-induced NF-kappaB activation in the pulmonary epithelium and, further, our understanding of its beneficial effects in hemorrhage-induced ALI.
Nydam
Trevor L
TL
Center for Trauma Research and Department of Surgery, University of Colorado Health Sciences Center, Denver, Colorado 80045, USA. Trevor.Nydam@UCHSC.edu
Moore
Ernest E
EE
McIntyre
Robert C
RC
Wright
Franklin L
FL
Gamboni-Robertson
Fabia
F
Eckels
Phillip C
PC
Banerjee
Anirban
A
D015153:Blotting, Western; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D008168:Lung / Q000166:cytology*; D008856:Microscopy, Fluorescence; D016328:NF-kappa B / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D012462:Saline Solution, Hypertonic / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D016328:NF-kappa B; D012462:Saline Solution, Hypertonic; D014409:Tumor Necrosis Factor-alpha